WO2019000112A1

WO2019000112A1 - Optimization method of aluminum alloy pipe argon arc welding process

Info

Publication number: WO2019000112A1
Application number: PCT/CN2017/000402
Authority: WO
Inventors: 张彬; 庞继勇; 陈雅斌; 郭利伟; 毛春生; 陈丽刚
Original assignee: 山东电力建设第一工程公司
Priority date: 2017-06-26
Filing date: 2017-06-26
Publication date: 2019-01-03

Abstract

The invention discloses an optimizing method of an aluminum alloy pipe argon arc welding process, comprising the following steps: performing a groove grinding treatment on tested pieces, wherein the groove angle is made to be 35 degrees, and after metal luster is shown, welding is performed within a set time; performing a vertical grouping inspection on the tested pieces on a station frame, inspecting whether gaps exist or not, and if the gaps exist, filing the groove edges to be flat; performing welding wire polishing, polishing a tungsten rod tungsten electrode of a welding gun into a conical shape, and performing welding under the conditions that a set argon purity, a set water content and a set gas flow are kept; grouping the prepared test pieces, no gaps are reserved during grouping, no corner deformation exists, and sequentially performing priming welding, weld joint junction and cover face welding; detecting the appearance of weld joints, detecting the interior quality through ray, transmitting different welded finished product data to a database, performing big data analysis, and according to data analysis, continuously adjusting and optimizing welding process parameters.

Description

Optimization method of argon arc welding process for aluminum alloy tube

Technical field

The invention relates to an optimization method for an argon arc welding process of an aluminum alloy tube.

Background technique

At present, in the national welding skill competition project, the welding of aluminum alloy pipe has become a regular competition project. Because aluminum and aluminum alloy have strong thermal conductivity, large heat capacity, large coefficient of linear expansion, low melting point and low temperature strength, The welding characteristics of aluminum tubes are prone to defects such as oxidation, pores and unfusion during welding. In the training process of the contestants, the traditional method is to follow the requirements of the competition technical documents, through the coaching experience and the welding exercises and personal exploration of the test pieces of the players, in order to summarize a set of welding techniques suitable for oneself for a long time, due to the level of the players. The difference leads to long training time, high material and mechanical use costs, and unstable welding quality when used on site. The argon arc welding process of aluminum alloy tubes and the effects of welding cannot be evaluated or evaluated fairly and objectively.

At the same time, the angle of the traditional specimen bevel processing is generally 30°, the welding angle is small under the butt joint, and the root is not welded and the defects are easily penetrated. At the same time, the bevel or the steel grinding head is used to polish the groove, so that the bevel edge exists. The burr is easy to damage the edge of the inner slope, resulting in defects such as pores and burn through during welding.

The quality of the welded joints is slow to increase, the time and energy spent by the operators are long, the cost of materials and machinery is high, and the long-term training is due to the strong light and strong ultraviolet radiation during welding of the aluminum alloy. The operator's physical and mental health causes damage.

Summary of the invention

In order to solve the above problems, the present invention proposes an optimization method for an argon arc welding process of an aluminum alloy tube, and the present invention provides a welding effect by setting a targeted welding method for several key technical points in the welding. Optimization, at the same time, can establish a unified evaluation criteria, a reasonable evaluation of the operator's level, can be applied to the welding skills competition project.

In order to achieve the above object, the present invention adopts the following technical solutions:

An optimization method for an argon arc welding process of an aluminum alloy tube, comprising the following steps:

(1) Grinding the test piece with a bevel, so that the groove angle is 35°, and the metal luster is exposed, and then welding is performed within a set time;

(2) Perform a vertical group check on the station frame to see if there is a gap, and if there is a gap, flatten the edge of the groove;

(3) Polishing the welding wire, grinding the tungsten rod of the welding torch into a round pile type, and performing welding under the set argon purity, water content and gas flow rate;

(4) The prepared test pieces are paired, no gap is left in the group, no angular deformation exists, and the bottom welding, the weld joint and the cover surface welding are sequentially performed;

(5) Detect the appearance of the weld and the internal quality of the ray inspection, transfer the data of different welding finished products to the database, perform big data analysis, and continuously adjust and optimize the welding process parameters according to the data analysis.

In the step (1), the test piece is polished by a super-hard tungsten steel circular saw blade for aluminum alloy, and the groove angle is 35° by the weld inspection rule inspection, and the inner groove edge is polished. Do not repair, keep it straight.

In the step (1), the surface of the test piece has a surface of 40-60 mm on both sides of the bevel, and the surface is polished with a steel grinding head to expose the metallic luster. The prepared test piece must be welded within 1.5-2.5 hours, otherwise the grinding is repeated. preparation.

In the step (3), the purity of the argon gas is not less than 99.99%, the water content is not more than 50 mg/m ³ , the gas flow rate is 15-20 L/min, and the ambient temperature is not lower than 5 ° C, otherwise preheating to 100- After 200 ° C, apply welding.

In the step (4), the welding current is 150-160A, the cleaning ratio is [-20, -15], and the AC bias value is 120; when welding, the welding gun is at an angle of 90° with the test piece, and cannot be tilted back and forth. The extension length of the tungsten electrode is [2, 4] mm, and the welding wire is at an angle of 50°-70° with the weld seam. When the wire is added, the molten pool melted by the wire top is used to add wire to the back of the molten pool.

In the step (4), during the welding process, the solder joints to be solidified are to be ground, and the root of the groove is not worn.

In the step (4), if it is found that there is a pore, immediately stop the welding, perform the grinding treatment, and check whether the root of the weld is not fused.

In the step (4), before the bottom weld joint, the super-hard tungsten steel circular saw blade is used to grind the front arc-extinguishing point out of the slope, and when the arc starts, the arc is to be arced behind the slope to form a molten pool. Add the welding wire for welding. At the end of the arc collection, the first arcing point should be polished out of the slope and slowly arced.

In the step (4), before the welding of the cover surface, the welding current is set to 140-150 A, the cleaning ratio is [-20, -5], and the AC bias value is 120.

In the step (4), when the cover surface is at an angle of 90° with the weld bead, the welding wire is applied at an angle of a shear line with the weld circle, and the welding gun is oscillated by a circular swing method, and the joint of the weld is made of tungsten. The steel circular saw blade is ground to ensure the height difference of the joint. The original weld seam should not be damaged when grinding. In the final arcing, the first arcing point should be polished out of the slope and slowly arced.

Compared with the prior art, the beneficial effects of the present invention are:

The invention adopts a super-hard tungsten steel circular saw blade for aluminum alloy to grind the groove, and has no burrs and notches on the edge of the groove to avoid defects such as pores and burn through when welding; the groove angle is 35°, and the test piece is solved. The angle of the groove is too small, which may cause defects such as insufficient penetration of the root.

The invention guides the operator's operation method throughout the welding process, so that each operator is easy to palm The welding skill of holding a uniform aluminum alloy tube ensures the appearance quality and internal quality of the welded joint.

Perform big data analysis on the welding effect of the operator, and continuously adjust and optimize the welding process parameters according to the data analysis to achieve the best welding effect, which helps to optimize the welding process.

Detailed ways:

The invention is further illustrated by the following examples.

It should be noted that the following detailed description is illustrative and is intended to provide a further description of the application. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise indicated.

It is to be noted that the terminology used herein is for the purpose of describing particular embodiments, and is not intended to limit the exemplary embodiments. As used herein, the singular " " " " " " There are features, steps, operations, devices, components, and/or combinations thereof.

As described in the background art, in the prior art, there is no fair and objective evaluation or evaluation of the argon arc welding process and the welding effect of the aluminum alloy tube, and the quality of the welded joint is improved slowly, and the time and energy spent by the operator are Longer, the cost of materials and machinery consumed is higher, and at the same time, due to the strong light and strong ultraviolet radiation during the welding of aluminum alloy, the training of the long-term injury to the operator's physical and mental health is insufficient, in order to solve the above technology. Problem, the present application proposes an optimization method for an argon arc welding process of an aluminum alloy tube, comprising the following steps:

(2) Perform a vertical group check on the station frame to see if there is a gap, if there is a seam The gap will flatten the edge of the groove;

In the step (4), if it is found that there is a pore, the welding is immediately stopped, the grinding treatment is performed, and the inspection is performed. Check if the root of the weld is not fused.

As a typical embodiment, the invention is used in competitions, the main equipment and materials required, and the welding method:

Welding equipment: AC/DC square wave aluminum welding machine;

Aluminum alloy tube specifications: Φ80 × 5mm, material: 5A06 aluminum-magnesium alloy;

Aluminum welding wire specification: 2.4mm, 3.2mm, model: SAl5356;

Welding method: AC tungsten argon arc welding;

Welding position: vertical fixed group pair welding;

Participants: Have a certain GTAW operational skills foundation.

Firstly, the test piece processed by the lathe is made of aluminum alloy special super-hard tungsten steel circular saw blade, and the groove is polished. The angle of the groove is 35°, and the inner edge of the groove is observed during the grinding. Do not repair and keep it straight. This processing method does not generate burrs at the groove, which can reduce the generation of air holes during welding. The surface of the 50mm side of the bevel of the test piece is polished with a steel grinding head to expose the metallic luster. The prepared test piece must be welded within 2 hours, otherwise it will be re-grinded, because aluminum It is easy to oxidize in the air to produce a dense oxide film. If it is not treated, it will cause pore defects during welding.

The test piece is vertically aligned on the station frame to see if there is a gap. If there is a gap that will cause burn-through defects, use a trowel to level the force slightly through the edge of the inner groove. The burrs that appear after grinding should be cleaned up, and as far as possible, no blunt edges will occur. Otherwise, the thick blunt edges will affect the bottom welding. Causes no penetration.

The wire used is polished with a steel ball to ensure that the surface of the wire is polished. The cleaned wire is placed in a special wire barrel and must be used within 8 hours. Otherwise, it will be easily oxidized and need to be reprocessed.

The tungsten rod of the welding torch is made of tantalum tungsten rod, and the tungsten pole is ground into a round pile type, which is not too sharp but smooth and has no edges and corners.

The purity of argon should not be lower than 99.99%, and the water content should not exceed 50 mg/m ³ , and the gas flow rate should be 15-20 L/min.

The ambient temperature should not be lower than 5 °C, otherwise it should be preheated to 100-200 °C before welding.

The prepared test pieces are paired, no gap is left in the pair, and there is no angular deformation.

Before the point is solid, reserve the arc starting point A, take the A point as the apex of the equilateral triangle, and determine the other two vertices B and C, that is, the two points that need to be solidified. The point solid current should not be too large, and cannot be welded. Fast and secure to prevent deformation or pulling when welding.

Before the bottom welding, set the welder current to 150-160A, the cleaning ratio is -20--15, and the AC bias value is 120.

The welding arc is at point A. The welding torch is at an angle of 90° to the test piece. It cannot be tilted back and forth, and the tungsten extension length is about 3 mm. The welding wire and the weld bead are at an angle of 50°-70°. When adding the wire, use a wire to gently melt the molten pool. Add wire to the back of the molten pool, do not add wire to the inside of the molten pool, and add wire to the inside of the molten pool. It is easy to cause the roots to be wireged. When starting the arc, the welding torch can be slightly oscillated up and down. Then the welding gun does not need to swing, and the welding speed should not be too slow. If the front molten pool is too thick and too wide after welding, it indicates that the root is not After penetration, the added wire melts into the molten pool on the surface.

During the welding process, the solder joints to be grounded should be ground, but the roots of the groove should not be worn through. If defects such as pores are found, stop the welding immediately, perform the grinding process, and check if the root of the weld is not fused.

Before the bottom weld joint, the front arc-extinguishing point is polished out of the slope with a super-hard tungsten steel circular saw blade, so that the joint is relatively easy. When starting the arc, the arc should be started behind the slope. After the molten pool is formed, the welding wire is added for welding. At the end of the arc, the first arcing point A is polished out of the slope, and the arc is slowly set, leaving a "small tail".

Before welding the cover, set the welder current to 140-150A, the cleaning ratio is -20--5, and the AC bias value is 120.

After the bottoming welding is completed, after the visual inspection is confirmed, the joints and high points of the bottom weld are slightly polished with a super-hard tungsten steel circular saw blade to smooth the underlying weld. When the surface is covered, the welding gun is at an angle of 90° with the weld. The welding wire can be wired at an angle to the shear line of the weld circle, and the welding gun is oscillated by a circular swing method. The joints of the welds are also ground with a super-hard tungsten steel circular saw blade to ensure the height difference of the joints, and the original welds that are not damaged when grinding. In the final arcing, the first arcing point should be polished out of the slope, and the arc should be slowly closed to close a small tail.

After the welding is completed, the internal quality of the appearance scoring and the radiographic inspection are carried out according to the criteria of the competition specification document. The database of the training process of the player is established, and the scores and problems of the welded specimens are entered into the database, and the training effect of the players is analyzed by big data. Constantly adjust and optimize the welding process parameters to achieve the best welding results and the best results.

The super-hard tungsten steel circular saw blade for aluminum alloy is used to grind the groove, and the groove angle is 35°. The test piece solves the defect that the root of the test piece is not penetrated due to the small angle of the groove of the test piece, if you want to let The root penetration will increase the current, which will cause the outer edge to be melted, the edge of the groove to be narrow and narrow, and the subsequent welding The seam cover has a great influence. At the same time, the current is too large to greatly increase the probability of generating pores inside the weld. If a boring tool or a steel grinding head is used to polish the groove, the burr is present on the edge of the groove and the inner edge of the groove is easily damaged, resulting in defects such as pores and burn through during welding.

The above description is only the preferred embodiment of the present application, and is not intended to limit the present application, and various changes and modifications may be made to the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application are intended to be included within the scope of the present application.

The above description of the specific embodiments of the present invention is not intended to limit the scope of the present invention, and those skilled in the art should understand that those skilled in the art can do without creative work on the basis of the technical solutions of the present invention. Various modifications or variations are still within the scope of the invention.

Claims

An optimization method for an argon arc welding process of an aluminum alloy tube, characterized in that the method comprises the following steps:

(1) Grinding the test piece with a bevel, so that the groove angle is 35°, and the metal luster is exposed, and then welding is performed within a set time;

(2) Perform a vertical group check on the station frame to see if there is a gap, and if there is a gap, flatten the edge of the groove;

(3) Polishing the welding wire, grinding the tungsten rod of the welding torch into a round pile type, and performing welding under the set argon purity, water content and gas flow rate;

(4) The prepared test pieces are paired, no gap is left in the group, no angular deformation exists, and the bottom welding, the weld joint and the cover surface welding are sequentially performed;

(5) Detect the appearance of the weld and the internal quality of the ray inspection, transfer the data of different welding finished products to the database, perform big data analysis, and continuously adjust and optimize the welding process parameters according to the data analysis.
The argon arc welding process optimization method for an aluminum alloy tube according to claim 1, wherein in the step (1), the test piece is polished by a super-hard tungsten steel circular saw blade for aluminum alloy. Through the inspection of the weld inspection, it is confirmed that the groove angle is 35°, and the inner groove edge is not repaired while being sanded, and is kept straight.
The method for optimizing the argon arc welding process of an aluminum alloy tube according to claim 1, wherein in the step (1), the surface of the test piece has a surface of 40-60 mm on both sides of the groove, and the surface is polished with a steel grinding head. Exposed to the metallic luster, the prepared test piece must be welded within 1.5-2.5 hours, otherwise it will be re-grinded.
The argon arc welding process optimization method for an aluminum alloy tube according to claim 1, wherein in the step (3), the purity of the argon gas is not less than 99.99%, and the water content is not more than 50 mg/m 3 . The gas flow rate is 15-20L/min, and the ambient temperature is not lower than 5 °C, otherwise it is preheated to 100-200 °C before welding.
The method for optimizing an argon arc welding process for an aluminum alloy tube according to claim 1, wherein in the step (4), the welding current is 150-160 A, and the cleaning ratio is [-20, -15]. The AC bias value is 120; when welding, the welding gun and the test piece are at an angle of 90°, which cannot be tilted back and forth. The extension length of the tungsten pole is [2, 4] mm, and the welding wire and the weld are at an angle of 50°-70°. When the wire is used, the molten pool melted by the wire top is used, and the wire is added to the back of the molten pool.
The method for optimizing an argon arc welding process for an aluminum alloy tube according to claim 1, wherein in the step (4), during the welding process, the solder joints to be solidified are to be ground, and the root of the groove is not to be Wear through.
The method for optimizing an argon arc welding process for an aluminum alloy tube according to claim 1, wherein in the step (4), if a pore is found, the welding is immediately stopped, the grinding treatment is performed, and the weld is inspected. Whether the root is not fused.
The argon arc welding process optimization method for an aluminum alloy tube according to claim 1, wherein in the step (4), before the bottom weld joint is used, a superhard tungsten steel circular saw blade is applied to the front side. The arc-extinguishing point is polished to the slope. When the arc is started, the arc is to be arced behind the slope. After the molten pool is formed, the welding wire is added for welding. At the end of the arc, the first arcing point is polished out of the slope and slowly arced.
The argon arc welding process optimization method for an aluminum alloy tube according to claim 1, wherein in the step (4), before the welding of the cover surface, the current of the welding machine is set to 140-150 A, and the cleaning ratio is [- 20, -5], the exchange bias is 120.
The argon arc welding process optimization method for an aluminum alloy tube according to claim 1, wherein in the step (4), the welding gun is at an angle of 90° with the weld seam when the surface is covered, and the welding wire is rounded with the weld seam. The angle of the cutting line is added, the welding gun is oscillated by the circular swing method, and the joint of the welded joint is polished by a tungsten steel circular saw blade to ensure the height difference of the joint, the original weld seam which is not damaged when grinding, and the final arcing time. The first arcing point should be polished out of the slope and slowly arced.